Personal protection strategies
One of the most reliable ways to minimise the risk of exposure to pest arthropods is to avoid their natural habitats (e.g. known mosquito or tick
habitats) or limit their ability to infest a house or workplace (e.g. bed bugs or bird mites). This relies on knowledge of the pest, their
natural habitats and environmental triggers for activity or population increases. For many pests, these factors may change depending on their
geographic distribution across Australia.
Insect repellents are usually applied to the skin to stop biting insects identifying the person as a potential blood meal. Repellents are often
used against biting midges, mosquitoes and ticks, although they can sometimes be used against other blood-feeding arthropods (e.g. bed bugs,
bird mites). Although the specific mode of action for many repellents is not fully understood, they usually stop the arthropod from biting
by either blocking the cues that identify the host as a potential blood meal or providing an odour that overrides that of the host. There is
a wide range of repellents available, classified as either synthetic or botanical in nature.
This term generally applies to chemically produced or synthesised repellents. The most effective and widely used repellent internationally is DEET
(diethyltoluamide). Developed by the United States Army in the 1950s, DEET is now used by many millions of people around the world and is available
in a wide range of application formulations (e.g. roll-ons, lotions, aerosols, pump-sprays and wipes) and concentrations. Generally, repellents
containing less than 10% DEET will offer up to two hours' protection from biting arthropods and are suitable for general use. Repellents that
contain up to 80% DEET are more suitable for long periods of exposure to biting arthropods in areas of endemic vector-borne disease.
Picaridin is another widely available active ingredient found in commercial insect repellents in Australia. This product was developed more recently,
is generally thought to have a more pleasant scent than DEET and has lower toxicity to humans (making it more appropriate for use on children).
Scientific studies have shown that this product is equally effective at preventing insect bites as DEET.
There are a large number of plants whose essential oils or extracts may provide protection against biting insects. The most common products come
from strongly aromatic plants, such as eucalypts or tea-tree, and commercial products often contain a blend of extracts. Many scientific studies
have compared botanical and synthetic repellents and, although botanical products may provide some protection, products such as DEET and picaridin
provide substantially greater and longer term protection, even at low concentrations. Some natural products offer protection for only a few
minutes, leaving users unprotected and exposed to disease-carrying vectors. However, research on repellents with botanical-based active ingredients
is continuing and these products may be useful under some circumstances.
Coils, sticks and other gadgets
Burning plant material to repel biting insects has been used by many cultures for thousands of years. Today, the tradition continues in the form
of mosquito coils and sticks. The mosquito coil is the most popular form of personal protection from biting insects over the past 100 years.
These devices are made of materials impregnated with insecticide (e.g. synthetic pyrethroids, such as allethrin) that burn slowly (some coils
burn for up to eight hours) and may provide up to 80% protection. Some formulations are also available with botanical active ingredients, but
these are generally less effective. Coils are cheap to produce and easy to operate, although the smoke produced may present a health risk when
used indoors. There is also a number of electronic units available (for both indoor and outdoor use) that release insecticides from slow-release
mats or liquids. These units can be very effective, as the pyrethroids kill mosquitoes rather than simply repelling them.
A wide range of products claim to repel biting insects in formulations other than topical repellents. Products containing synthetic or botanical
active ingredients can include patches and wrist bands that claim to provide a degree of protection. However, scientific studies have shown
that these products offer substantially less protection than topical repellents.
All repellents used in Australia, whether synthetic or botanical, must by law be registered with the APVMA and the approval number must be listed
on the label.
There is often a perception that synthetic repellents, such as DEET, are unsafe. However, despite the widespread use of DEET-based products internationally,
there are very few cases of adverse reactions. Most of these cases involve serious misuse, most commonly applying too much of the product (especially
on young children), eating it or exposing the eyes to the product. Botanical-based products can also cause irritation. The risk of an adverse
reaction from using a repellent is very low and failing to use repellents in some locations will almost certainly result in insect bites and
the real possibility of acquiring an infectious disease.
Regardless of the active ingredient, all repellents should be applied according to the instructions on the label.
All insecticides must be registered with the APVMA for use in Australia. Detailed discussion of the most suitable products for controlling specific
pests is beyond the scope of this document and professional pest managers may be needed to treat serious infestations. However, in many cases,
household insecticides (either knockdown aerosols or long-lasting residual surface sprays) may be a cost-effective solution to lessen the short-term
effects of some biting arthropods. The one notable exception to this is for bed bugs, as household products are generally ineffective and can
cause the infestation to spread, making eradication more difficult and expensive.
Physical and chemical barriers against pests are often very effective. Screened windows, doorways and balconies, and bed nets provide protection
from flying insects, and insecticide applications to the building or surrounding vegetation may provide further protection. Some vertebrate
animals, such as bandicoots, rodents and birds can carry arthropod pests; barriers that stop these animals from entering properties are often
the best way to minimise the risks of exposure to these arthropods.
Many electronic (e.g. ultrasonic) devices are available that claim to repel invertebrate and vertebrate pests, but these have repeatedly been shown
to be ineffective. These devices continue to be adapted to new technologies with options available for mobile phones, portable music players
and other digital devices but, unfortunately, no new advances in their actual repellent properties have been made.
Traps and lures
A wide variety of traps and lures are designed to control arthropod pests. These traps and lures vary greatly, not only in their design and mode
of action (e.g. electrocuting lights, carbon dioxide-baited suction traps, sticky paper, shelter providers), but also in their effectiveness
in controlling pests. Although many of these devices collect pest arthropods, few offer complete protection from pest effects, long-term population
control or eradication. However, they may be an important component of integrated pest management strategies and can be a useful tool in monitoring
One of the most effective tools to assist personal protection is knowledge. Information about locally important pests and their biology, ecology
and potential health impacts will allow the individual to better avoid exposure to the pests' bites, stings and disease-causing microorganisms.
It is hoped that this document will go some way towards improving the availability of knowledge on many of Australia's most important arthropod
Source: Australian Government Department of Health